Auto-complete in traits

Is it possible to make the IDE recognize that a trait will be used in a certain context? For example, I have a trait that adds more assertions for unit testing that looks like:

 
trait assertHeaders
{
    protected function assertHeaderStatus($iStatusCode)
    {
        $this->assertEquals($iStatusCode, http_response_code());
    }

    protected function assertHeaderSet($strKey, $mValue)
    {
        $aHeaders = [];
        foreach(xdebug_get_headers() as $strHeader)
        {
            $aHeader = explode(':',$strHeader);
            $aHeaders[$aHeader[0]] = $aHeader[1];
        }

        $this->assertArrayHasKey($strKey, $aHeaders);
        $this->assertContains($mValue, $aHeaders[$strKey]);
    }
}

It will only ever be used in a unit testing context IE:
 
class BaseControllerTest extends PHPUnit_Framework_TestCase
{
    use assertHeaders;
 
    // Tests go here
}

However, the assert calls within the trait are not recognized. I'm wondering if there's a way to make this possible? Some fancy docblock or setting I'm missing would be great. If not, the only way to make auto-complete work is to do say UnitTestAssertHeaders extends PHPUnit_Framework_TestCase, but this leads to not being able to easily use multiple custom assertions, since PHP does not allow multiple inheritance.